Re: [avr-chat] usbasp

[Neil Davey]

Hi all,
It should be noted that the usbasp desing will work ok with usb1.1 
ports, but you *may* find that usb2 port complain....
I built this for use under windows, on an older machine with usb1.1 
ports, no problems, detected and installed drivers..
On my new laptop with usb2 ports it didn't detect properly and wouldn't 
install drivers.

After looking closer to the circuit diagram, and also emailing Objective 
Developments (creators of the AVR USB) with the design running at 5V the 
signal levels on the usb bus are out of specification for usb2. You can 
either install a 3.5V voltage regulator into the circuit, as per 
Objective Developments examples or a suggestion from Objective 
Developments that I have not tried is to change the values of R6 and R7 
to try and bring the line voltages back into spec.

I added a 3.3V regulator to the circuit and it worked fine on usb2 
ports. Of course it you are using a 5V target circuit this is a problem.
Just my experience with this... YMMV

Regards
Neil Davey

> > On Wed, 08 Mar 2006 09:07:45 +0530, <address@hidden> wrote:
> >    
> >
> > > What about
> > > www.fischl.de/usbasp
> > >
> > > I did it myself. It works on my laptop without any problem.
> > > Javier
> > >      
> > This looks nice & simple. When I build it, I'll get back to you with my 
> > feedback.
> > Thanks !!
> >
> > --Royce.
> >
> >    
> >
> > > "Royce Pereira" <address@hidden>@nongnu.org con fecha 07/03/2006
> > > 04:29:18 a.m.
> > >
> > >
> > > Hi,
> > > Can any one recommend a AVR programmer using the USB port? I need something
> > > I can build myself, not buy commercially.
> > >      
>
>
> I built one and it seems to work out of the box. My system is linux 2.6.14.
> Because I could not read the layout on Thomas Fischls homepage I built my
> own postscript based pcb. Here is the source:
>
>
>  


--
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Neil Davey
Griffith University

Griffith School of Engineering
Nathan Campus
Phone: 07-3735-7008
Fax: 07-3735-5112

School of Psychology - ACNRC
Mt Gravatt Campus
Phone: 07-3735-3395
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